Average cross-sections for (n, α) and (n, p) reactions on titanium in a fission-type reactor spectrum

Abstract

The average cross-section in a fission-type reactor spectrum was determined experimentally for the reactions:46Ti(n,p)46Sc,47Ti(n,p)47Sc,48Ti(n,p)48Ti(n,α)45Ca and50Ti(n,α)47Ca. In order to obtain the (n,p) cross-sections, reactor irradiation of titanium was followed by measurement of the induced scandium activities with a Ge(Li) detector of calibrated detection efficiency. For this no chemical separations had to be carried out. For the (n,α) reactions, however, the induced calcium activities were separeted and purified by oxalate precipitation, after the bulk of the radioactivity had been removed by precipitation of titanium hydroxide. The47Ca disintegration rate was determined in the same way as for the scandium isotopes, whereas for45Ca liquid scintillation counting was carried out. The shape of the reactor spectrum was investigated by irradiating reference threshold detectors with different effective threshold energies. To correct for (n,γ) interferences, irradiations were carried out with and without cadmium shielding. On the basis of\(\bar \sigma _F = 0.64\) mb for the reaction27Al(n,α)24Na, the average cross-sections were as follows:46Ti(n,p)46Sc:10.5±0.4 mb;47Ti(n,p)47Sc: 16.3±0.6 mb;48Ti(n,p)48Sc:0.272±0.005 mb;48Ti(n,α)45Ca: 34μb;50Ti(n,α)47Ca: 8.1±0.3 μb.